Which of the Following Statements Is NOT True

Which of the following statements is NOT true?

A) Smooth muscle can be classified according to the timing and means of increasing cytosolic Ca²⁺.
B) In smooth muscle, C-type Ca²⁺ channels regulate the influx of extracellular Ca^2+.
C) Smooth muscle tone exists because the muscle has a relatively low resting potential.
D) In smooth muscle, Ca2+ binds directly to myosin light chain kinase as opposed to troponin as it does in skeletal muscle.
E) Skeletal, cardiac, and smooth muscle differ in the energy source used for contraction.